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Merge branch 'i2c-fixes-rc6' of git://aeryn.fluff.org.uk/bjdooks/linux
[linux-2.6/mini2440.git] / drivers / md / dm-ioctl.c
blob7f77f18fcafa662e07139600716865780c1afcdc
1 /*
2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8 #include "dm.h"
9
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/miscdevice.h>
13 #include <linux/init.h>
14 #include <linux/wait.h>
15 #include <linux/slab.h>
16 #include <linux/dm-ioctl.h>
17 #include <linux/hdreg.h>
18 #include <linux/compat.h>
19
20 #include <asm/uaccess.h>
21
22 #define DM_MSG_PREFIX "ioctl"
23 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
24
25 /*-----------------------------------------------------------------
26 * The ioctl interface needs to be able to look up devices by
27 * name or uuid.
28 *---------------------------------------------------------------*/
29 struct hash_cell {
30 struct list_head name_list;
31 struct list_head uuid_list;
32
33 char *name;
34 char *uuid;
35 struct mapped_device *md;
36 struct dm_table *new_map;
37 };
38
39 struct vers_iter {
40 size_t param_size;
41 struct dm_target_versions *vers, *old_vers;
42 char *end;
43 uint32_t flags;
44 };
45
46
47 #define NUM_BUCKETS 64
48 #define MASK_BUCKETS (NUM_BUCKETS - 1)
49 static struct list_head _name_buckets[NUM_BUCKETS];
50 static struct list_head _uuid_buckets[NUM_BUCKETS];
51
52 static void dm_hash_remove_all(int keep_open_devices);
53
54 /*
55 * Guards access to both hash tables.
56 */
57 static DECLARE_RWSEM(_hash_lock);
58
59 static void init_buckets(struct list_head *buckets)
60 {
61 unsigned int i;
62
63 for (i = 0; i < NUM_BUCKETS; i++)
64 INIT_LIST_HEAD(buckets + i);
65 }
66
67 static int dm_hash_init(void)
68 {
69 init_buckets(_name_buckets);
70 init_buckets(_uuid_buckets);
71 return 0;
72 }
73
74 static void dm_hash_exit(void)
75 {
76 dm_hash_remove_all(0);
77 }
78
79 /*-----------------------------------------------------------------
80 * Hash function:
81 * We're not really concerned with the str hash function being
82 * fast since it's only used by the ioctl interface.
83 *---------------------------------------------------------------*/
84 static unsigned int hash_str(const char *str)
85 {
86 const unsigned int hash_mult = 2654435387U;
87 unsigned int h = 0;
88
89 while (*str)
90 h = (h + (unsigned int) *str++) * hash_mult;
91
92 return h & MASK_BUCKETS;
93 }
94
95 /*-----------------------------------------------------------------
96 * Code for looking up a device by name
97 *---------------------------------------------------------------*/
98 static struct hash_cell *__get_name_cell(const char *str)
99 {
100 struct hash_cell *hc;
101 unsigned int h = hash_str(str);
102
103 list_for_each_entry (hc, _name_buckets + h, name_list)
104 if (!strcmp(hc->name, str)) {
105 dm_get(hc->md);
106 return hc;
107 }
108
109 return NULL;
110 }
111
112 static struct hash_cell *__get_uuid_cell(const char *str)
113 {
114 struct hash_cell *hc;
115 unsigned int h = hash_str(str);
116
117 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
118 if (!strcmp(hc->uuid, str)) {
119 dm_get(hc->md);
120 return hc;
121 }
122
123 return NULL;
124 }
125
126 /*-----------------------------------------------------------------
127 * Inserting, removing and renaming a device.
128 *---------------------------------------------------------------*/
129 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
130 struct mapped_device *md)
131 {
132 struct hash_cell *hc;
133
134 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
135 if (!hc)
136 return NULL;
137
138 hc->name = kstrdup(name, GFP_KERNEL);
139 if (!hc->name) {
140 kfree(hc);
141 return NULL;
142 }
143
144 if (!uuid)
145 hc->uuid = NULL;
146
147 else {
148 hc->uuid = kstrdup(uuid, GFP_KERNEL);
149 if (!hc->uuid) {
150 kfree(hc->name);
151 kfree(hc);
152 return NULL;
153 }
154 }
155
156 INIT_LIST_HEAD(&hc->name_list);
157 INIT_LIST_HEAD(&hc->uuid_list);
158 hc->md = md;
159 hc->new_map = NULL;
160 return hc;
161 }
162
163 static void free_cell(struct hash_cell *hc)
164 {
165 if (hc) {
166 kfree(hc->name);
167 kfree(hc->uuid);
168 kfree(hc);
169 }
170 }
171
172 /*
173 * The kdev_t and uuid of a device can never change once it is
174 * initially inserted.
175 */
176 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
177 {
178 struct hash_cell *cell, *hc;
179
180 /*
181 * Allocate the new cells.
182 */
183 cell = alloc_cell(name, uuid, md);
184 if (!cell)
185 return -ENOMEM;
186
187 /*
188 * Insert the cell into both hash tables.
189 */
190 down_write(&_hash_lock);
191 hc = __get_name_cell(name);
192 if (hc) {
193 dm_put(hc->md);
194 goto bad;
195 }
196
197 list_add(&cell->name_list, _name_buckets + hash_str(name));
198
199 if (uuid) {
200 hc = __get_uuid_cell(uuid);
201 if (hc) {
202 list_del(&cell->name_list);
203 dm_put(hc->md);
204 goto bad;
205 }
206 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
207 }
208 dm_get(md);
209 dm_set_mdptr(md, cell);
210 up_write(&_hash_lock);
211
212 return 0;
213
214 bad:
215 up_write(&_hash_lock);
216 free_cell(cell);
217 return -EBUSY;
218 }
219
220 static void __hash_remove(struct hash_cell *hc)
221 {
222 struct dm_table *table;
223
224 /* remove from the dev hash */
225 list_del(&hc->uuid_list);
226 list_del(&hc->name_list);
227 dm_set_mdptr(hc->md, NULL);
228
229 table = dm_get_table(hc->md);
230 if (table) {
231 dm_table_event(table);
232 dm_table_put(table);
233 }
234
235 if (hc->new_map)
236 dm_table_destroy(hc->new_map);
237 dm_put(hc->md);
238 free_cell(hc);
239 }
240
241 static void dm_hash_remove_all(int keep_open_devices)
242 {
243 int i, dev_skipped, dev_removed;
244 struct hash_cell *hc;
245 struct list_head *tmp, *n;
246
247 down_write(&_hash_lock);
248
249 retry:
250 dev_skipped = dev_removed = 0;
251 for (i = 0; i < NUM_BUCKETS; i++) {
252 list_for_each_safe (tmp, n, _name_buckets + i) {
253 hc = list_entry(tmp, struct hash_cell, name_list);
254
255 if (keep_open_devices &&
256 dm_lock_for_deletion(hc->md)) {
257 dev_skipped++;
258 continue;
259 }
260 __hash_remove(hc);
261 dev_removed = 1;
262 }
263 }
264
265 /*
266 * Some mapped devices may be using other mapped devices, so if any
267 * still exist, repeat until we make no further progress.
268 */
269 if (dev_skipped) {
270 if (dev_removed)
271 goto retry;
272
273 DMWARN("remove_all left %d open device(s)", dev_skipped);
274 }
275
276 up_write(&_hash_lock);
277 }
278
279 static int dm_hash_rename(uint32_t cookie, const char *old, const char *new)
280 {
281 char *new_name, *old_name;
282 struct hash_cell *hc;
283 struct dm_table *table;
284
285 /*
286 * duplicate new.
287 */
288 new_name = kstrdup(new, GFP_KERNEL);
289 if (!new_name)
290 return -ENOMEM;
291
292 down_write(&_hash_lock);
293
294 /*
295 * Is new free ?
296 */
297 hc = __get_name_cell(new);
298 if (hc) {
299 DMWARN("asked to rename to an already existing name %s -> %s",
300 old, new);
301 dm_put(hc->md);
302 up_write(&_hash_lock);
303 kfree(new_name);
304 return -EBUSY;
305 }
306
307 /*
308 * Is there such a device as 'old' ?
309 */
310 hc = __get_name_cell(old);
311 if (!hc) {
312 DMWARN("asked to rename a non existent device %s -> %s",
313 old, new);
314 up_write(&_hash_lock);
315 kfree(new_name);
316 return -ENXIO;
317 }
318
319 /*
320 * rename and move the name cell.
321 */
322 list_del(&hc->name_list);
323 old_name = hc->name;
324 hc->name = new_name;
325 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
326
327 /*
328 * Wake up any dm event waiters.
329 */
330 table = dm_get_table(hc->md);
331 if (table) {
332 dm_table_event(table);
333 dm_table_put(table);
334 }
335
336 dm_kobject_uevent(hc->md, KOBJ_CHANGE, cookie);
337
338 dm_put(hc->md);
339 up_write(&_hash_lock);
340 kfree(old_name);
341 return 0;
342 }
343
344 /*-----------------------------------------------------------------
345 * Implementation of the ioctl commands
346 *---------------------------------------------------------------*/
347 /*
348 * All the ioctl commands get dispatched to functions with this
349 * prototype.
350 */
351 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
352
353 static int remove_all(struct dm_ioctl *param, size_t param_size)
354 {
355 dm_hash_remove_all(1);
356 param->data_size = 0;
357 return 0;
358 }
359
360 /*
361 * Round up the ptr to an 8-byte boundary.
362 */
363 #define ALIGN_MASK 7
364 static inline void *align_ptr(void *ptr)
365 {
366 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
367 }
368
369 /*
370 * Retrieves the data payload buffer from an already allocated
371 * struct dm_ioctl.
372 */
373 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
374 size_t *len)
375 {
376 param->data_start = align_ptr(param + 1) - (void *) param;
377
378 if (param->data_start < param_size)
379 *len = param_size - param->data_start;
380 else
381 *len = 0;
382
383 return ((void *) param) + param->data_start;
384 }
385
386 static int list_devices(struct dm_ioctl *param, size_t param_size)
387 {
388 unsigned int i;
389 struct hash_cell *hc;
390 size_t len, needed = 0;
391 struct gendisk *disk;
392 struct dm_name_list *nl, *old_nl = NULL;
393
394 down_write(&_hash_lock);
395
396 /*
397 * Loop through all the devices working out how much
398 * space we need.
399 */
400 for (i = 0; i < NUM_BUCKETS; i++) {
401 list_for_each_entry (hc, _name_buckets + i, name_list) {
402 needed += sizeof(struct dm_name_list);
403 needed += strlen(hc->name) + 1;
404 needed += ALIGN_MASK;
405 }
406 }
407
408 /*
409 * Grab our output buffer.
410 */
411 nl = get_result_buffer(param, param_size, &len);
412 if (len < needed) {
413 param->flags |= DM_BUFFER_FULL_FLAG;
414 goto out;
415 }
416 param->data_size = param->data_start + needed;
417
418 nl->dev = 0; /* Flags no data */
419
420 /*
421 * Now loop through filling out the names.
422 */
423 for (i = 0; i < NUM_BUCKETS; i++) {
424 list_for_each_entry (hc, _name_buckets + i, name_list) {
425 if (old_nl)
426 old_nl->next = (uint32_t) ((void *) nl -
427 (void *) old_nl);
428 disk = dm_disk(hc->md);
429 nl->dev = huge_encode_dev(disk_devt(disk));
430 nl->next = 0;
431 strcpy(nl->name, hc->name);
432
433 old_nl = nl;
434 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
435 }
436 }
437
438 out:
439 up_write(&_hash_lock);
440 return 0;
441 }
442
443 static void list_version_get_needed(struct target_type *tt, void *needed_param)
444 {
445 size_t *needed = needed_param;
446
447 *needed += sizeof(struct dm_target_versions);
448 *needed += strlen(tt->name);
449 *needed += ALIGN_MASK;
450 }
451
452 static void list_version_get_info(struct target_type *tt, void *param)
453 {
454 struct vers_iter *info = param;
455
456 /* Check space - it might have changed since the first iteration */
457 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
458 info->end) {
459
460 info->flags = DM_BUFFER_FULL_FLAG;
461 return;
462 }
463
464 if (info->old_vers)
465 info->old_vers->next = (uint32_t) ((void *)info->vers -
466 (void *)info->old_vers);
467 info->vers->version[0] = tt->version[0];
468 info->vers->version[1] = tt->version[1];
469 info->vers->version[2] = tt->version[2];
470 info->vers->next = 0;
471 strcpy(info->vers->name, tt->name);
472
473 info->old_vers = info->vers;
474 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
475 }
476
477 static int list_versions(struct dm_ioctl *param, size_t param_size)
478 {
479 size_t len, needed = 0;
480 struct dm_target_versions *vers;
481 struct vers_iter iter_info;
482
483 /*
484 * Loop through all the devices working out how much
485 * space we need.
486 */
487 dm_target_iterate(list_version_get_needed, &needed);
488
489 /*
490 * Grab our output buffer.
491 */
492 vers = get_result_buffer(param, param_size, &len);
493 if (len < needed) {
494 param->flags |= DM_BUFFER_FULL_FLAG;
495 goto out;
496 }
497 param->data_size = param->data_start + needed;
498
499 iter_info.param_size = param_size;
500 iter_info.old_vers = NULL;
501 iter_info.vers = vers;
502 iter_info.flags = 0;
503 iter_info.end = (char *)vers+len;
504
505 /*
506 * Now loop through filling out the names & versions.
507 */
508 dm_target_iterate(list_version_get_info, &iter_info);
509 param->flags |= iter_info.flags;
510
511 out:
512 return 0;
513 }
514
515
516
517 static int check_name(const char *name)
518 {
519 if (strchr(name, '/')) {
520 DMWARN("invalid device name");
521 return -EINVAL;
522 }
523
524 return 0;
525 }
526
527 /*
528 * Fills in a dm_ioctl structure, ready for sending back to
529 * userland.
530 */
531 static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
532 {
533 struct gendisk *disk = dm_disk(md);
534 struct dm_table *table;
535
536 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
537 DM_ACTIVE_PRESENT_FLAG);
538
539 if (dm_suspended(md))
540 param->flags |= DM_SUSPEND_FLAG;
541
542 param->dev = huge_encode_dev(disk_devt(disk));
543
544 /*
545 * Yes, this will be out of date by the time it gets back
546 * to userland, but it is still very useful for
547 * debugging.
548 */
549 param->open_count = dm_open_count(md);
550
551 if (get_disk_ro(disk))
552 param->flags |= DM_READONLY_FLAG;
553
554 param->event_nr = dm_get_event_nr(md);
555
556 table = dm_get_table(md);
557 if (table) {
558 param->flags |= DM_ACTIVE_PRESENT_FLAG;
559 param->target_count = dm_table_get_num_targets(table);
560 dm_table_put(table);
561 } else
562 param->target_count = 0;
563
564 return 0;
565 }
566
567 static int dev_create(struct dm_ioctl *param, size_t param_size)
568 {
569 int r, m = DM_ANY_MINOR;
570 struct mapped_device *md;
571
572 r = check_name(param->name);
573 if (r)
574 return r;
575
576 if (param->flags & DM_PERSISTENT_DEV_FLAG)
577 m = MINOR(huge_decode_dev(param->dev));
578
579 r = dm_create(m, &md);
580 if (r)
581 return r;
582
583 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
584 if (r) {
585 dm_put(md);
586 return r;
587 }
588
589 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
590
591 r = __dev_status(md, param);
592 dm_put(md);
593
594 return r;
595 }
596
597 /*
598 * Always use UUID for lookups if it's present, otherwise use name or dev.
599 */
600 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
601 {
602 struct mapped_device *md;
603 void *mdptr = NULL;
604
605 if (*param->uuid)
606 return __get_uuid_cell(param->uuid);
607
608 if (*param->name)
609 return __get_name_cell(param->name);
610
611 md = dm_get_md(huge_decode_dev(param->dev));
612 if (!md)
613 goto out;
614
615 mdptr = dm_get_mdptr(md);
616 if (!mdptr)
617 dm_put(md);
618
619 out:
620 return mdptr;
621 }
622
623 static struct mapped_device *find_device(struct dm_ioctl *param)
624 {
625 struct hash_cell *hc;
626 struct mapped_device *md = NULL;
627
628 down_read(&_hash_lock);
629 hc = __find_device_hash_cell(param);
630 if (hc) {
631 md = hc->md;
632
633 /*
634 * Sneakily write in both the name and the uuid
635 * while we have the cell.
636 */
637 strncpy(param->name, hc->name, sizeof(param->name));
638 if (hc->uuid)
639 strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1);
640 else
641 param->uuid[0] = '\0';
642
643 if (hc->new_map)
644 param->flags |= DM_INACTIVE_PRESENT_FLAG;
645 else
646 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
647 }
648 up_read(&_hash_lock);
649
650 return md;
651 }
652
653 static int dev_remove(struct dm_ioctl *param, size_t param_size)
654 {
655 struct hash_cell *hc;
656 struct mapped_device *md;
657 int r;
658
659 down_write(&_hash_lock);
660 hc = __find_device_hash_cell(param);
661
662 if (!hc) {
663 DMWARN("device doesn't appear to be in the dev hash table.");
664 up_write(&_hash_lock);
665 return -ENXIO;
666 }
667
668 md = hc->md;
669
670 /*
671 * Ensure the device is not open and nothing further can open it.
672 */
673 r = dm_lock_for_deletion(md);
674 if (r) {
675 DMWARN("unable to remove open device %s", hc->name);
676 up_write(&_hash_lock);
677 dm_put(md);
678 return r;
679 }
680
681 __hash_remove(hc);
682 up_write(&_hash_lock);
683
684 dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr);
685
686 dm_put(md);
687 param->data_size = 0;
688 return 0;
689 }
690
691 /*
692 * Check a string doesn't overrun the chunk of
693 * memory we copied from userland.
694 */
695 static int invalid_str(char *str, void *end)
696 {
697 while ((void *) str < end)
698 if (!*str++)
699 return 0;
700
701 return -EINVAL;
702 }
703
704 static int dev_rename(struct dm_ioctl *param, size_t param_size)
705 {
706 int r;
707 char *new_name = (char *) param + param->data_start;
708
709 if (new_name < param->data ||
710 invalid_str(new_name, (void *) param + param_size) ||
711 strlen(new_name) > DM_NAME_LEN - 1) {
712 DMWARN("Invalid new logical volume name supplied.");
713 return -EINVAL;
714 }
715
716 r = check_name(new_name);
717 if (r)
718 return r;
719
720 param->data_size = 0;
721 return dm_hash_rename(param->event_nr, param->name, new_name);
722 }
723
724 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
725 {
726 int r = -EINVAL, x;
727 struct mapped_device *md;
728 struct hd_geometry geometry;
729 unsigned long indata[4];
730 char *geostr = (char *) param + param->data_start;
731
732 md = find_device(param);
733 if (!md)
734 return -ENXIO;
735
736 if (geostr < param->data ||
737 invalid_str(geostr, (void *) param + param_size)) {
738 DMWARN("Invalid geometry supplied.");
739 goto out;
740 }
741
742 x = sscanf(geostr, "%lu %lu %lu %lu", indata,
743 indata + 1, indata + 2, indata + 3);
744
745 if (x != 4) {
746 DMWARN("Unable to interpret geometry settings.");
747 goto out;
748 }
749
750 if (indata[0] > 65535 || indata[1] > 255 ||
751 indata[2] > 255 || indata[3] > ULONG_MAX) {
752 DMWARN("Geometry exceeds range limits.");
753 goto out;
754 }
755
756 geometry.cylinders = indata[0];
757 geometry.heads = indata[1];
758 geometry.sectors = indata[2];
759 geometry.start = indata[3];
760
761 r = dm_set_geometry(md, &geometry);
762 if (!r)
763 r = __dev_status(md, param);
764
765 param->data_size = 0;
766
767 out:
768 dm_put(md);
769 return r;
770 }
771
772 static int do_suspend(struct dm_ioctl *param)
773 {
774 int r = 0;
775 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
776 struct mapped_device *md;
777
778 md = find_device(param);
779 if (!md)
780 return -ENXIO;
781
782 if (param->flags & DM_SKIP_LOCKFS_FLAG)
783 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
784 if (param->flags & DM_NOFLUSH_FLAG)
785 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
786
787 if (!dm_suspended(md))
788 r = dm_suspend(md, suspend_flags);
789
790 if (!r)
791 r = __dev_status(md, param);
792
793 dm_put(md);
794 return r;
795 }
796
797 static int do_resume(struct dm_ioctl *param)
798 {
799 int r = 0;
800 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
801 struct hash_cell *hc;
802 struct mapped_device *md;
803 struct dm_table *new_map;
804
805 down_write(&_hash_lock);
806
807 hc = __find_device_hash_cell(param);
808 if (!hc) {
809 DMWARN("device doesn't appear to be in the dev hash table.");
810 up_write(&_hash_lock);
811 return -ENXIO;
812 }
813
814 md = hc->md;
815
816 new_map = hc->new_map;
817 hc->new_map = NULL;
818 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
819
820 up_write(&_hash_lock);
821
822 /* Do we need to load a new map ? */
823 if (new_map) {
824 /* Suspend if it isn't already suspended */
825 if (param->flags & DM_SKIP_LOCKFS_FLAG)
826 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
827 if (param->flags & DM_NOFLUSH_FLAG)
828 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
829 if (!dm_suspended(md))
830 dm_suspend(md, suspend_flags);
831
832 r = dm_swap_table(md, new_map);
833 if (r) {
834 dm_table_destroy(new_map);
835 dm_put(md);
836 return r;
837 }
838
839 if (dm_table_get_mode(new_map) & FMODE_WRITE)
840 set_disk_ro(dm_disk(md), 0);
841 else
842 set_disk_ro(dm_disk(md), 1);
843 }
844
845 if (dm_suspended(md))
846 r = dm_resume(md);
847
848
849 if (!r) {
850 dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr);
851 r = __dev_status(md, param);
852 }
853
854 dm_put(md);
855 return r;
856 }
857
858 /*
859 * Set or unset the suspension state of a device.
860 * If the device already is in the requested state we just return its status.
861 */
862 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
863 {
864 if (param->flags & DM_SUSPEND_FLAG)
865 return do_suspend(param);
866
867 return do_resume(param);
868 }
869
870 /*
871 * Copies device info back to user space, used by
872 * the create and info ioctls.
873 */
874 static int dev_status(struct dm_ioctl *param, size_t param_size)
875 {
876 int r;
877 struct mapped_device *md;
878
879 md = find_device(param);
880 if (!md)
881 return -ENXIO;
882
883 r = __dev_status(md, param);
884 dm_put(md);
885 return r;
886 }
887
888 /*
889 * Build up the status struct for each target
890 */
891 static void retrieve_status(struct dm_table *table,
892 struct dm_ioctl *param, size_t param_size)
893 {
894 unsigned int i, num_targets;
895 struct dm_target_spec *spec;
896 char *outbuf, *outptr;
897 status_type_t type;
898 size_t remaining, len, used = 0;
899
900 outptr = outbuf = get_result_buffer(param, param_size, &len);
901
902 if (param->flags & DM_STATUS_TABLE_FLAG)
903 type = STATUSTYPE_TABLE;
904 else
905 type = STATUSTYPE_INFO;
906
907 /* Get all the target info */
908 num_targets = dm_table_get_num_targets(table);
909 for (i = 0; i < num_targets; i++) {
910 struct dm_target *ti = dm_table_get_target(table, i);
911
912 remaining = len - (outptr - outbuf);
913 if (remaining <= sizeof(struct dm_target_spec)) {
914 param->flags |= DM_BUFFER_FULL_FLAG;
915 break;
916 }
917
918 spec = (struct dm_target_spec *) outptr;
919
920 spec->status = 0;
921 spec->sector_start = ti->begin;
922 spec->length = ti->len;
923 strncpy(spec->target_type, ti->type->name,
924 sizeof(spec->target_type));
925
926 outptr += sizeof(struct dm_target_spec);
927 remaining = len - (outptr - outbuf);
928 if (remaining <= 0) {
929 param->flags |= DM_BUFFER_FULL_FLAG;
930 break;
931 }
932
933 /* Get the status/table string from the target driver */
934 if (ti->type->status) {
935 if (ti->type->status(ti, type, outptr, remaining)) {
936 param->flags |= DM_BUFFER_FULL_FLAG;
937 break;
938 }
939 } else
940 outptr[0] = '\0';
941
942 outptr += strlen(outptr) + 1;
943 used = param->data_start + (outptr - outbuf);
944
945 outptr = align_ptr(outptr);
946 spec->next = outptr - outbuf;
947 }
948
949 if (used)
950 param->data_size = used;
951
952 param->target_count = num_targets;
953 }
954
955 /*
956 * Wait for a device to report an event
957 */
958 static int dev_wait(struct dm_ioctl *param, size_t param_size)
959 {
960 int r;
961 struct mapped_device *md;
962 struct dm_table *table;
963
964 md = find_device(param);
965 if (!md)
966 return -ENXIO;
967
968 /*
969 * Wait for a notification event
970 */
971 if (dm_wait_event(md, param->event_nr)) {
972 r = -ERESTARTSYS;
973 goto out;
974 }
975
976 /*
977 * The userland program is going to want to know what
978 * changed to trigger the event, so we may as well tell
979 * him and save an ioctl.
980 */
981 r = __dev_status(md, param);
982 if (r)
983 goto out;
984
985 table = dm_get_table(md);
986 if (table) {
987 retrieve_status(table, param, param_size);
988 dm_table_put(table);
989 }
990
991 out:
992 dm_put(md);
993 return r;
994 }
995
996 static inline fmode_t get_mode(struct dm_ioctl *param)
997 {
998 fmode_t mode = FMODE_READ | FMODE_WRITE;
999
1000 if (param->flags & DM_READONLY_FLAG)
1001 mode = FMODE_READ;
1002
1003 return mode;
1004 }
1005
1006 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1007 struct dm_target_spec **spec, char **target_params)
1008 {
1009 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1010 *target_params = (char *) (*spec + 1);
1011
1012 if (*spec < (last + 1))
1013 return -EINVAL;
1014
1015 return invalid_str(*target_params, end);
1016 }
1017
1018 static int populate_table(struct dm_table *table,
1019 struct dm_ioctl *param, size_t param_size)
1020 {
1021 int r;
1022 unsigned int i = 0;
1023 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1024 uint32_t next = param->data_start;
1025 void *end = (void *) param + param_size;
1026 char *target_params;
1027
1028 if (!param->target_count) {
1029 DMWARN("populate_table: no targets specified");
1030 return -EINVAL;
1031 }
1032
1033 for (i = 0; i < param->target_count; i++) {
1034
1035 r = next_target(spec, next, end, &spec, &target_params);
1036 if (r) {
1037 DMWARN("unable to find target");
1038 return r;
1039 }
1040
1041 r = dm_table_add_target(table, spec->target_type,
1042 (sector_t) spec->sector_start,
1043 (sector_t) spec->length,
1044 target_params);
1045 if (r) {
1046 DMWARN("error adding target to table");
1047 return r;
1048 }
1049
1050 next = spec->next;
1051 }
1052
1053 r = dm_table_set_type(table);
1054 if (r) {
1055 DMWARN("unable to set table type");
1056 return r;
1057 }
1058
1059 return dm_table_complete(table);
1060 }
1061
1062 static int table_prealloc_integrity(struct dm_table *t,
1063 struct mapped_device *md)
1064 {
1065 struct list_head *devices = dm_table_get_devices(t);
1066 struct dm_dev_internal *dd;
1067
1068 list_for_each_entry(dd, devices, list)
1069 if (bdev_get_integrity(dd->dm_dev.bdev))
1070 return blk_integrity_register(dm_disk(md), NULL);
1071
1072 return 0;
1073 }
1074
1075 static int table_load(struct dm_ioctl *param, size_t param_size)
1076 {
1077 int r;
1078 struct hash_cell *hc;
1079 struct dm_table *t;
1080 struct mapped_device *md;
1081
1082 md = find_device(param);
1083 if (!md)
1084 return -ENXIO;
1085
1086 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1087 if (r)
1088 goto out;
1089
1090 r = populate_table(t, param, param_size);
1091 if (r) {
1092 dm_table_destroy(t);
1093 goto out;
1094 }
1095
1096 r = table_prealloc_integrity(t, md);
1097 if (r) {
1098 DMERR("%s: could not register integrity profile.",
1099 dm_device_name(md));
1100 dm_table_destroy(t);
1101 goto out;
1102 }
1103
1104 r = dm_table_alloc_md_mempools(t);
1105 if (r) {
1106 DMWARN("unable to allocate mempools for this table");
1107 dm_table_destroy(t);
1108 goto out;
1109 }
1110
1111 down_write(&_hash_lock);
1112 hc = dm_get_mdptr(md);
1113 if (!hc || hc->md != md) {
1114 DMWARN("device has been removed from the dev hash table.");
1115 dm_table_destroy(t);
1116 up_write(&_hash_lock);
1117 r = -ENXIO;
1118 goto out;
1119 }
1120
1121 if (hc->new_map)
1122 dm_table_destroy(hc->new_map);
1123 hc->new_map = t;
1124 up_write(&_hash_lock);
1125
1126 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1127 r = __dev_status(md, param);
1128
1129 out:
1130 dm_put(md);
1131
1132 return r;
1133 }
1134
1135 static int table_clear(struct dm_ioctl *param, size_t param_size)
1136 {
1137 int r;
1138 struct hash_cell *hc;
1139 struct mapped_device *md;
1140
1141 down_write(&_hash_lock);
1142
1143 hc = __find_device_hash_cell(param);
1144 if (!hc) {
1145 DMWARN("device doesn't appear to be in the dev hash table.");
1146 up_write(&_hash_lock);
1147 return -ENXIO;
1148 }
1149
1150 if (hc->new_map) {
1151 dm_table_destroy(hc->new_map);
1152 hc->new_map = NULL;
1153 }
1154
1155 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1156
1157 r = __dev_status(hc->md, param);
1158 md = hc->md;
1159 up_write(&_hash_lock);
1160 dm_put(md);
1161 return r;
1162 }
1163
1164 /*
1165 * Retrieves a list of devices used by a particular dm device.
1166 */
1167 static void retrieve_deps(struct dm_table *table,
1168 struct dm_ioctl *param, size_t param_size)
1169 {
1170 unsigned int count = 0;
1171 struct list_head *tmp;
1172 size_t len, needed;
1173 struct dm_dev_internal *dd;
1174 struct dm_target_deps *deps;
1175
1176 deps = get_result_buffer(param, param_size, &len);
1177
1178 /*
1179 * Count the devices.
1180 */
1181 list_for_each (tmp, dm_table_get_devices(table))
1182 count++;
1183
1184 /*
1185 * Check we have enough space.
1186 */
1187 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1188 if (len < needed) {
1189 param->flags |= DM_BUFFER_FULL_FLAG;
1190 return;
1191 }
1192
1193 /*
1194 * Fill in the devices.
1195 */
1196 deps->count = count;
1197 count = 0;
1198 list_for_each_entry (dd, dm_table_get_devices(table), list)
1199 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1200
1201 param->data_size = param->data_start + needed;
1202 }
1203
1204 static int table_deps(struct dm_ioctl *param, size_t param_size)
1205 {
1206 int r = 0;
1207 struct mapped_device *md;
1208 struct dm_table *table;
1209
1210 md = find_device(param);
1211 if (!md)
1212 return -ENXIO;
1213
1214 r = __dev_status(md, param);
1215 if (r)
1216 goto out;
1217
1218 table = dm_get_table(md);
1219 if (table) {
1220 retrieve_deps(table, param, param_size);
1221 dm_table_put(table);
1222 }
1223
1224 out:
1225 dm_put(md);
1226 return r;
1227 }
1228
1229 /*
1230 * Return the status of a device as a text string for each
1231 * target.
1232 */
1233 static int table_status(struct dm_ioctl *param, size_t param_size)
1234 {
1235 int r;
1236 struct mapped_device *md;
1237 struct dm_table *table;
1238
1239 md = find_device(param);
1240 if (!md)
1241 return -ENXIO;
1242
1243 r = __dev_status(md, param);
1244 if (r)
1245 goto out;
1246
1247 table = dm_get_table(md);
1248 if (table) {
1249 retrieve_status(table, param, param_size);
1250 dm_table_put(table);
1251 }
1252
1253 out:
1254 dm_put(md);
1255 return r;
1256 }
1257
1258 /*
1259 * Pass a message to the target that's at the supplied device offset.
1260 */
1261 static int target_message(struct dm_ioctl *param, size_t param_size)
1262 {
1263 int r, argc;
1264 char **argv;
1265 struct mapped_device *md;
1266 struct dm_table *table;
1267 struct dm_target *ti;
1268 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1269
1270 md = find_device(param);
1271 if (!md)
1272 return -ENXIO;
1273
1274 r = __dev_status(md, param);
1275 if (r)
1276 goto out;
1277
1278 if (tmsg < (struct dm_target_msg *) param->data ||
1279 invalid_str(tmsg->message, (void *) param + param_size)) {
1280 DMWARN("Invalid target message parameters.");
1281 r = -EINVAL;
1282 goto out;
1283 }
1284
1285 r = dm_split_args(&argc, &argv, tmsg->message);
1286 if (r) {
1287 DMWARN("Failed to split target message parameters");
1288 goto out;
1289 }
1290
1291 table = dm_get_table(md);
1292 if (!table)
1293 goto out_argv;
1294
1295 ti = dm_table_find_target(table, tmsg->sector);
1296 if (!dm_target_is_valid(ti)) {
1297 DMWARN("Target message sector outside device.");
1298 r = -EINVAL;
1299 } else if (ti->type->message)
1300 r = ti->type->message(ti, argc, argv);
1301 else {
1302 DMWARN("Target type does not support messages");
1303 r = -EINVAL;
1304 }
1305
1306 dm_table_put(table);
1307 out_argv:
1308 kfree(argv);
1309 out:
1310 param->data_size = 0;
1311 dm_put(md);
1312 return r;
1313 }
1314
1315 /*-----------------------------------------------------------------
1316 * Implementation of open/close/ioctl on the special char
1317 * device.
1318 *---------------------------------------------------------------*/
1319 static ioctl_fn lookup_ioctl(unsigned int cmd)
1320 {
1321 static struct {
1322 int cmd;
1323 ioctl_fn fn;
1324 } _ioctls[] = {
1325 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1326 {DM_REMOVE_ALL_CMD, remove_all},
1327 {DM_LIST_DEVICES_CMD, list_devices},
1328
1329 {DM_DEV_CREATE_CMD, dev_create},
1330 {DM_DEV_REMOVE_CMD, dev_remove},
1331 {DM_DEV_RENAME_CMD, dev_rename},
1332 {DM_DEV_SUSPEND_CMD, dev_suspend},
1333 {DM_DEV_STATUS_CMD, dev_status},
1334 {DM_DEV_WAIT_CMD, dev_wait},
1335
1336 {DM_TABLE_LOAD_CMD, table_load},
1337 {DM_TABLE_CLEAR_CMD, table_clear},
1338 {DM_TABLE_DEPS_CMD, table_deps},
1339 {DM_TABLE_STATUS_CMD, table_status},
1340
1341 {DM_LIST_VERSIONS_CMD, list_versions},
1342
1343 {DM_TARGET_MSG_CMD, target_message},
1344 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1345 };
1346
1347 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1348 }
1349
1350 /*
1351 * As well as checking the version compatibility this always
1352 * copies the kernel interface version out.
1353 */
1354 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1355 {
1356 uint32_t version[3];
1357 int r = 0;
1358
1359 if (copy_from_user(version, user->version, sizeof(version)))
1360 return -EFAULT;
1361
1362 if ((DM_VERSION_MAJOR != version[0]) ||
1363 (DM_VERSION_MINOR < version[1])) {
1364 DMWARN("ioctl interface mismatch: "
1365 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1366 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1367 DM_VERSION_PATCHLEVEL,
1368 version[0], version[1], version[2], cmd);
1369 r = -EINVAL;
1370 }
1371
1372 /*
1373 * Fill in the kernel version.
1374 */
1375 version[0] = DM_VERSION_MAJOR;
1376 version[1] = DM_VERSION_MINOR;
1377 version[2] = DM_VERSION_PATCHLEVEL;
1378 if (copy_to_user(user->version, version, sizeof(version)))
1379 return -EFAULT;
1380
1381 return r;
1382 }
1383
1384 static void free_params(struct dm_ioctl *param)
1385 {
1386 vfree(param);
1387 }
1388
1389 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1390 {
1391 struct dm_ioctl tmp, *dmi;
1392
1393 if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
1394 return -EFAULT;
1395
1396 if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
1397 return -EINVAL;
1398
1399 dmi = vmalloc(tmp.data_size);
1400 if (!dmi)
1401 return -ENOMEM;
1402
1403 if (copy_from_user(dmi, user, tmp.data_size)) {
1404 vfree(dmi);
1405 return -EFAULT;
1406 }
1407
1408 *param = dmi;
1409 return 0;
1410 }
1411
1412 static int validate_params(uint cmd, struct dm_ioctl *param)
1413 {
1414 /* Always clear this flag */
1415 param->flags &= ~DM_BUFFER_FULL_FLAG;
1416
1417 /* Ignores parameters */
1418 if (cmd == DM_REMOVE_ALL_CMD ||
1419 cmd == DM_LIST_DEVICES_CMD ||
1420 cmd == DM_LIST_VERSIONS_CMD)
1421 return 0;
1422
1423 if ((cmd == DM_DEV_CREATE_CMD)) {
1424 if (!*param->name) {
1425 DMWARN("name not supplied when creating device");
1426 return -EINVAL;
1427 }
1428 } else if ((*param->uuid && *param->name)) {
1429 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1430 return -EINVAL;
1431 }
1432
1433 /* Ensure strings are terminated */
1434 param->name[DM_NAME_LEN - 1] = '\0';
1435 param->uuid[DM_UUID_LEN - 1] = '\0';
1436
1437 return 0;
1438 }
1439
1440 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1441 {
1442 int r = 0;
1443 unsigned int cmd;
1444 struct dm_ioctl *uninitialized_var(param);
1445 ioctl_fn fn = NULL;
1446 size_t param_size;
1447
1448 /* only root can play with this */
1449 if (!capable(CAP_SYS_ADMIN))
1450 return -EACCES;
1451
1452 if (_IOC_TYPE(command) != DM_IOCTL)
1453 return -ENOTTY;
1454
1455 cmd = _IOC_NR(command);
1456
1457 /*
1458 * Check the interface version passed in. This also
1459 * writes out the kernel's interface version.
1460 */
1461 r = check_version(cmd, user);
1462 if (r)
1463 return r;
1464
1465 /*
1466 * Nothing more to do for the version command.
1467 */
1468 if (cmd == DM_VERSION_CMD)
1469 return 0;
1470
1471 fn = lookup_ioctl(cmd);
1472 if (!fn) {
1473 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1474 return -ENOTTY;
1475 }
1476
1477 /*
1478 * Trying to avoid low memory issues when a device is
1479 * suspended.
1480 */
1481 current->flags |= PF_MEMALLOC;
1482
1483 /*
1484 * Copy the parameters into kernel space.
1485 */
1486 r = copy_params(user, &param);
1487
1488 current->flags &= ~PF_MEMALLOC;
1489
1490 if (r)
1491 return r;
1492
1493 r = validate_params(cmd, param);
1494 if (r)
1495 goto out;
1496
1497 param_size = param->data_size;
1498 param->data_size = sizeof(*param);
1499 r = fn(param, param_size);
1500
1501 /*
1502 * Copy the results back to userland.
1503 */
1504 if (!r && copy_to_user(user, param, param->data_size))
1505 r = -EFAULT;
1506
1507 out:
1508 free_params(param);
1509 return r;
1510 }
1511
1512 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1513 {
1514 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1515 }
1516
1517 #ifdef CONFIG_COMPAT
1518 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1519 {
1520 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1521 }
1522 #else
1523 #define dm_compat_ctl_ioctl NULL
1524 #endif
1525
1526 static const struct file_operations _ctl_fops = {
1527 .unlocked_ioctl = dm_ctl_ioctl,
1528 .compat_ioctl = dm_compat_ctl_ioctl,
1529 .owner = THIS_MODULE,
1530 };
1531
1532 static struct miscdevice _dm_misc = {
1533 .minor = MISC_DYNAMIC_MINOR,
1534 .name = DM_NAME,
1535 .devnode = "mapper/control",
1536 .fops = &_ctl_fops
1537 };
1538
1539 /*
1540 * Create misc character device and link to DM_DIR/control.
1541 */
1542 int __init dm_interface_init(void)
1543 {
1544 int r;
1545
1546 r = dm_hash_init();
1547 if (r)
1548 return r;
1549
1550 r = misc_register(&_dm_misc);
1551 if (r) {
1552 DMERR("misc_register failed for control device");
1553 dm_hash_exit();
1554 return r;
1555 }
1556
1557 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1558 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1559 DM_DRIVER_EMAIL);
1560 return 0;
1561 }
1562
1563 void dm_interface_exit(void)
1564 {
1565 if (misc_deregister(&_dm_misc) < 0)
1566 DMERR("misc_deregister failed for control device");
1567
1568 dm_hash_exit();
1569 }
1570
1571 /**
1572 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1573 * @md: Pointer to mapped_device
1574 * @name: Buffer (size DM_NAME_LEN) for name
1575 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1576 */
1577 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1578 {
1579 int r = 0;
1580 struct hash_cell *hc;
1581
1582 if (!md)
1583 return -ENXIO;
1584
1585 dm_get(md);
1586 down_read(&_hash_lock);
1587 hc = dm_get_mdptr(md);
1588 if (!hc || hc->md != md) {
1589 r = -ENXIO;
1590 goto out;
1591 }
1592
1593 if (name)
1594 strcpy(name, hc->name);
1595 if (uuid)
1596 strcpy(uuid, hc->uuid ? : "");
1597
1598 out:
1599 up_read(&_hash_lock);
1600 dm_put(md);
1601
1602 return r;
1603 }
Support for the Chinese Samsung S3C2440 based development boards